As skeptical as we generally are about surrounding the iPhone 4 with potentially signal-reducing aluminum, that's exactly what Artwizz has done with its SeeJacket Alu ($25). Available in six colors, this case comes with three pieces: the metal shell itself, as well as black and white silicone inserts. Both pieces are quite thin and feel somewhat cheap on their own; when they're put together, they don't feel any thicker than a standard case.

While we initially expected a very tight fit, inserting an iPhone 4 into SeeJacket Alu is really quite easy. The silicone inserts are very malleable—floppy, even—so the phone slips right in, and the metal shell fits over that. It takes a bit of a push, but goes on readily enough. Seven nubs along the tall edges then hold the two pieces together. There are holes for the side switch and volume buttons sized specifically for the GSM-version of the iPhone 4, no surprise given Artwizz’s German roots, as well as long openings along the top and bottom edges that allow full access to the buttons and ports. The rubber also extends a bit over the glass display to create a small protective lip. Note that no screen protection is included in the package.

Our biggest concern with the metal back was signal blockage. In our testing, the iPhone 4 inside SeeJacket Alu did sometimes drop one bar of Wi-Fi relative to an unencased iPhone 4, but this wasn’t consistently the case; signal strength is only modestly weaker. Thankfully, we observed no difference at all in cellular signal between our control unit and the encased iPhone 4. Overall, the impact the case has on the signal is small.

For $25, SeeJacket Alu isn’t a bad deal. The combination of metal and rubber is pretty unique, and we’re happy that it doesn’t wreck the iPhone 4’s wireless performance. Button coverage and a bit more material along the top and bottom edges would increase the otherwise good level of protection. Actually buying the case may be a little more of a challenge: outside the U.S., it’s available for €25 directly from Artwizz, and though it’s supposed to be sold here by Harmonic Inversion Technology, we haven’t seen it listed on the company’s web site. Due to its nice design, SeeJacket Alu is worthy of a general recommendation; if you can find it and like the metal elements, you’ll find it to be a pretty good choice.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
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